See how you go with 2 simple questions :)
Who did Christ in Acts 9:15, Rom 11:13, Rom 15:16 chose a Apostle & Minister to you ?
Who did ALL the Apostles in Gal 2:7-9 agree teaches you the Gospel
Galatians 2:7-9 does not say Paul was the only one appointed to preach the gospel to gentiles. Just as it does not say Peter was the only one appointed to preach the gospel to the Jews.
Peter preached to Cornelius, a Roman soldier.
Phillip preached to the Ethiopian eunuch.
7 But contrariwise, when they saw that the gospel of the uncircumcision was committed unto me, as the gospel of the circumcision was unto Peter;
8 (For he that wrought effectually in Peter to the apostleship of the circumcision, the same was mighty in me toward the Gentiles:)
9 And when James, Cephas, and John, who seemed to be pillars, perceived the grace that was given unto me, they gave to me and Barnabas the right hands of fellowship; that we should go unto the heathen, and they unto the circumcision.